The first movie will be Big Daddy, starring Adam Sandler.  It's regarded as a modern comedic classic by many and it's one of my personal favorites. 

It is the story of a man-child, named Sonny, who gets the surprise of a lifetime when the child of his roomate, Julian, shows up on his doorstep.  In order to impress a girl, he adopts the child (fraudulantly, I might add) and learns a lot about himself and responsibility along the way.  It's laugh out loud and totally heartfelt.
I LOVE THIS MOVIE! I saw it for the first time, in the theatres, when I was only five years old and have just loved it ever since. I give it the full 5 stars.
One of my favorite scenes from any movie comes from Big Daddy. It is the scene taht takes place on Halloween.  Sonny takes Julian trick-or-treating for the first time, where they come in contact with a crabby old man who refuses to answer the door.  He is on the phone and gestures through the window for the pair to leave.  Two minutes later, we see Sonny in the house with the man, who is petrified and winds up giving little Julian everything he can find, including his expensive watch.  This scene was so funny and made the movie perfect in my eyes!